fix(postinstall): fix typo in name

Author: bmuenzenmeyer

packages/plugin-tab/postinstall.js

@@ -1,5 +1,5 @@
 console.log(`Pattern Lab Node Plugin - "plugin-tab" installed.
-Use the CLI to install this: patternlab install --plugins @pattern-lab/tab
+Use the CLI to install this: patternlab install --plugins @pattern-lab/plugin-tab
 Configure or disable this plugin inside your patternlab-config.json file.
 Add tabs to the Pattern Lab UI by adding file extensions to the "tabsToAdd" array on the plugins['@pattern-lab/plugin-tab'].options object.
 `);